Is there a software integration guide for RM1xx-M2 concentrator card?

RM1xx-M.2 is a peripheral hardware, and all the software should be running in your host (as like BT stack is running on host) and the integration process should be dependent on what packet forwarder you want to use. Refer to integration guide from a network server of your choice for more details regarding this. 

You would also need the underlying libloragw library (basically the HAL layer) which is available in https://github.com/Lora-net/lora_gateway.